Firefighters extinguish blaze after explosion at the Chevron plant in Pembroke Dock, south-west Wales Two people have been killed in a major explosion at an oil refinery in south-west Wales. It is understood that two petrol tankers collided inside the Chevron plant in Pembroke Dock, killing both the drivers. One of the tankers was completely destroyed in the explosion, according to Mid and West Wales fire and rescue service. A spokesman for the Welsh Ambulance Service confirmed that paramedics had dealt with casualties at the scene and the air ambulance was deployed. Because of the heat of the flames, it is not yet certain how many people have been hurt, he added. A Mid and West Wales fire and rescue service spokeswoman said the fires had been extinguished. She added that the other tanker was damaged in the blast and was being examined by fire crews. “It was a major fire and we have 26 firefighters there and 16 specialist crew,” the spokeswoman said. She added that there had so far been no oil spillage or environmental damage. Staff at Milford Haven Coastguard, which is based across a stretch of water from the refinery, heard an explosion and saw a plume of black smoke, which is now dying down. A spokesman said: “There was a bang that was heard and there was smoke billowing.” A spokesman for Chevron said: “At 18:20 local time on June 2 2011 an incident occurred at the Pembroke Refinery. “Emergency services were called and responded immediately and remain on the scene. The fire has been extinguished. “We are taking appropriate action to respond to the situation. We are still in the process of accounting for all personnel.” The Pembroke Dock refinery specialises in processing heavy, lower quality crude oil. Wales Oil and gas companies Oil Chevron David Batty guardian.co.uk